Right now, electronics are built to last. Soon, however, their lifespan might be more fleeting — courtesy of burgeoning research into "transient electronics," or devices meant to serve a specific function before completely dissolving into their environment over a predetermined span of weeks, months, or even years. In fact, your own body might be one of the first places these devices are deployed.
"Electronics that disappear in a way that's programmable and controlled."
"The goal of the electronics industry has always been to build durable devices that last forever and perform consistently," John Rogers, Ph.D., a materials scientist at the University of Illinois at Urbana-Champaign, told The Verge. "But imagine the possibilities once you start thinking about electronics that disappear in a way that's programmable and controlled." Rogers is leading a team of materials scientists and biomedical engineers from across the country in the development of such gadgets.
One day they may transform the consumer electronics industry. But researchers are currently more interested in the devices' potential for medical care, like implantable sensors or drug dispensers, as well as military exploits and environmental monitoring.
Research into such devices has made rapid progress, meaning that preliminary versions of vanishing electronics might be available within the next few years. In a presentation at the annual conference of the American Chemical Society, Rogers shared tantalizing details of new progress in transient electronic development, including successful tests on animal subjects and wireless power systems integrated into the devices, offering energy without relying on an external electricity source.
"We're coming along quickly," he said. "I don't want to give a specific timetable, but I can say that we're already a long way from where we were even a few months ago."
Rogers first started investigating transient electronics in 2008, and worked with a grant from military research agency DARPA to develop preliminary iterations of the devices. In September of last year, he and a consortium of researchers published a paper in Science outlining several key breakthroughs, most notably the development of integrated circuit boards capable of dissolving in water or bodily fluid at a controlled rate of degradation.
Rogers and colleagues had to re-imagine every single component of an electronic
To come up with the devices in the first place, Rogers and colleagues had to re-imagine every single component of an electronic gadget, from semiconductors to power supply systems, in order to flip the standards of conventional electronics — durability and long lifespan — on their heads. The devices rely on an eclectic combination of biocompatible materials: silicon, already an industry standard in conventional integrated circuits, is spliced into ultra-thin dissolvable layers; magnesium acts as a conductor; and layers of magnesium oxide and silk encase the entire device. The lifespan of a given gadget will depend on how thick that outer layer is, but could theoretically range from hours to years.
Rogers and his team have now successfully implanted one type of transient device into a mouse, where the implant killed off bacteria around a surgical wound site — a process that typically relies on antibiotics — before dissolving. Where medical care is concerned, different iterations of the devices would circumvent existing challenges that hamper existing implantable electronics, namely concerns over long-term effects inside the body, as well as painful or costly implant removal and replacement.
"That's a pretty game-changing application."
They've also devised two different systems to fuel the devices: a wireless power system that converts radio frequency energy into DC power, and another that harvests power through movement. Rogers anticipates the latter being particularly helpful inside the human body. "Imagine you insert something into the heart, the heart is beating, and you're able to generate energy from that movement," he said. "That's a pretty game-changing application."
The military is also taking note of that game-changing potential. DARPA earlier this year solicited research proposals for a new program, called Vanishing Programmable Resources (VAPR), that aims to devise transient electronics for national defense.
Rogers, whose team applied for funding through the initiative, declined to specify what those applications might be. The DARPA program announcement, however, mentions a desire for "remote sensing and communications devices" that don't need to be collected once they've completed a task — suggesting that surveillance is a top priority. Rogers and his team, it's worth noting, have already designed a transient, 64-pixel digital camera. "With regards to the military, I'm not at liberty to tell you what the most important applications might be," Rogers noted. "But I'm sure you can imagine."